I am familiar with both packages, having used them extensively. Admittedly my IDL experience was before DX.
The packages are more complementary than competitive. In fact, an interface between the two was written over 5 years ago. For many reasons it wouldn't work with the current version of either package and would not be the best approach. Here are some points: o IDL is limited on the types of data it handles directly -- regular grids. This is due to its notion of arrays (not unlike a scalar array object in DX). Anything more complex like a tensor array, field or group in DX, a tetrahedral mesh, etc. is an exercise left to the user (i.e., the difference between having and not having a data model) o IDL is stronger on analysis tools. This is not an architectural limitation with DX, just what's been implemented as modules/macros. o DX is stronger on 3d visualization. The techniques in IDL are very limited o DX has integrated viewing and interaction. IDL has it separate for vector, pixel, or OpenGL. o DX enables development from an API, scripting language and visual programming. IDL primarily has a language like the DX script, which has more programming constructs but more primitive data type than DX. RSI has recently added a visual programming interface, but they've not addressed the issues that are handled by the DX executive that are needed for it to be useful. o DX is parallelized for SMPs (e.g., SGI servers). IDL has no support for parallel platforms. I hope this helps. Of course, an irony here is that a limitation in how DX could be used in the past was due to licensing, which have been eliminated with open source. Those same limitations still apply to IDL. Johannes-Maria Kaltenbach <[EMAIL PROTECTED]>@opendx.watson.ibm.com on 03/13/2000 06:40:27 AM Please respond to [email protected] Sent by: [EMAIL PROTECTED] To: [email protected] cc: Subject: [opendx-general] general question to OpenDX; comparison with IDL Hello, I hope this is the right forum to ask the following question; I'm not (yet) a user of OpenDX. In the course of the purchase of a new mainframe our departement plans to replace our own (very old and uncomfortable) graphics system. A colleague of mine has compared several commercial systems and it seems that the decision will be for IDL (of Research Systems Inc.). Since I'm generally in favour of OpenSource I asked for a broader comparison. The proposition of using OpenGL (or Mesa) + GLUT and create a taylor-made system by ourselves was not accepted. The system has to have more 'high level' features and should provide some kind of scripting language (i. e. should be comparable to IDL). The only system I found that could probably meet this requirements is OpenDX. I tried to install it on our old HP computer but failed (and I've no time left trying to install it; the installation of Mesa was succesful). Therefore I've got a PC to install Linux and OpendDX on it to try if it could meet our expectations (but I've at most this one week to do perform the test by myself; then the we must decide finally what system we will install). Since I doubt that this time will be sufficient and having no prior knowledge of OpenDX I hope that I can get some useful information from experi- enced OpenDX users. Has anyone on this list experience with both IDL and OpenDX or can anyone point me to some place where I can get some relevant information on this point? [Some information to our computing environment: we use a central multi-processor HP/Convex computer (which will in the near future be replaced by two SGI computers); some users (like myself) are logged in from their HP workstations, but most users either have an HP terminal or a PC. The PC guys don't use Linux, but NT and Exceed. Typically there are about 50 users logged in.] Johannes-Maria -- Dr. Johannes-Maria Kaltenbach Address: D-73446 Oberkochen, Germany Carl Zeiss Phone : ++49-(0)7364-204086 Optical Design Department Fax : ++49-(0)7364-202285 Research & Technology Division E-Mail : [EMAIL PROTECTED]
